In a molten salt gasification process for producing a combustible gas from a solid sulfur-containing carbonaceous fuel, the fuel is partially oxidized with oxygen in a gasifier in the presence of molten alkali metal salts. The fuel can be coal, petroleum coke or another solid combustible material that contains sulfur and carbon. The products of the gasification reaction include the combustible gases, such as CO and H2, and sulfur or sulfur containing material. The molten salts may include alkali metal carbonate, which acts as a catalyst for the gasification reaction and absorbs sulfur to form molten sulfur salt, thus reducing sulfur content in the gas product.
In a known technique, the fuel and carbonate salt are added to the gasifier in solid form. Such a technique has some drawbacks. For example, when the pressure in the gasifier is high, feeding solid fuel and salt into the gasifier is difficult and requires substantial equipment and operational cost. If the pressure in the gasifier is lowered, a larger gasifier is required to maintain the same production rate. Further, sticking and plugging can occur in the solid feed lines, particularly when water vapor is present.
It is thus desirable to provide an improved molten salt process for producing combustible gases from sulfur-containing carbonaceous fuels.